Ejected by a solar storm, a coil of plasma--charged particles--spins outward in this November 2007 optical-wavelength image (and the picture on the next page) captured by NASA's twin STEREO spacecraft. STEREO images like this have been used to create the first 3-D pictures of solar storms, NASA announced on April 14, 2009.

The structure of each "coronal mass ejection" includes a "magnetic flux rope"--a physical wave that behaves like a Slinky toy, transporting material from the solar surface into the sun's atmosphere and then flinging the material into space, suggested Angelos Vourlidas, a solar physicist at the Naval Research Laboratory in Washington, D.C., and a STEREO project scientist.

"With STEREO we can now derive the 3-D shape of that Slinky," Vourlidas said. "We actually call it a croissant.